/*
Copyright (c) 2007-2017, Troy D. Hanson   http://troydhanson.github.com/uthash/
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef UTLIST_H
#define UTLIST_H

#define UTLIST_VERSION 2.0.2

#include <assert.h>

/*
 * This file contains macros to manipulate singly and doubly-linked lists.
 *
 * 1. LL_ macros:  singly-linked lists.
 * 2. DL_ macros:  doubly-linked lists.
 * 3. CDL_ macros: circular doubly-linked lists.
 *
 * To use singly-linked lists, your structure must have a "next" pointer.
 * To use doubly-linked lists, your structure must "prev" and "next" pointers.
 * Either way, the pointer to the head of the list must be initialized to NULL.
 *
 * ----------------.EXAMPLE -------------------------
 * struct item {
 *      int id;
 *      struct item *prev, *next;
 * }
 *
 * struct item *list = NULL:
 *
 * int main() {
 *      struct item *item;
 *      ... allocate and populate item ...
 *      DL_APPEND(list, item);
 * }
 * --------------------------------------------------
 *
 * For doubly-linked lists, the append and delete macros are O(1)
 * For singly-linked lists, append and delete are O(n) but prepend is O(1)
 * The sort macro is O(n log(n)) for all types of single/double/circular lists.
 */

/* These macros use decltype or the earlier __typeof GNU extension.
   As decltype is only available in newer compilers (VS2010 or gcc 4.3+
   when compiling c++ source) this code uses whatever method is needed
   or, for VS2008 where neither is available, uses casting workarounds. */
#if !defined(LDECLTYPE) && !defined(NO_DECLTYPE)
#if defined(_MSC_VER)                        /* MS compiler */
#if _MSC_VER >= 1600 && defined(__cplusplus) /* VS2010 or newer in C++ mode */
#define LDECLTYPE(x) decltype(x)
#else /* VS2008 or older (or VS2010 in C mode) */
#define NO_DECLTYPE
#endif
#elif defined(__BORLANDC__) || defined(__ICCARM__) || defined(__LCC__) || defined(__WATCOMC__)
#define NO_DECLTYPE
#else /* GNU, Sun and other compilers */
#define LDECLTYPE(x) __typeof(x)
#endif
#endif

/* for VS2008 we use some workarounds to get around the lack of decltype,
 * namely, we always reassign our tmp variable to the list head if we need
 * to dereference its prev/next pointers, and save/restore the real head.*/
#ifdef NO_DECLTYPE
#define IF_NO_DECLTYPE(x) x
#define LDECLTYPE(x) char *
#define UTLIST_SV(elt, list)                                                                       \
	_tmp = (char *)(list);                                                                         \
	{                                                                                              \
		char **_alias = (char **)&(list);                                                          \
		*_alias = (elt);                                                                           \
	}
#define UTLIST_NEXT(elt, list, next) ((char *)((list)->next))
#define UTLIST_NEXTASGN(elt, list, to, next)                                                       \
	{                                                                                              \
		char **_alias = (char **)&((list)->next);                                                  \
		*_alias = (char *)(to);                                                                    \
	}
/* #define UTLIST_PREV(elt,list,prev) ((char*)((list)->prev)) */
#define UTLIST_PREVASGN(elt, list, to, prev)                                                       \
	{                                                                                              \
		char **_alias = (char **)&((list)->prev);                                                  \
		*_alias = (char *)(to);                                                                    \
	}
#define UTLIST_RS(list)                                                                            \
	{                                                                                              \
		char **_alias = (char **)&(list);                                                          \
		*_alias = _tmp;                                                                            \
	}
#define UTLIST_CASTASGN(a, b)                                                                      \
	{                                                                                              \
		char **_alias = (char **)&(a);                                                             \
		*_alias = (char *)(b);                                                                     \
	}
#else
#define IF_NO_DECLTYPE(x)
#define UTLIST_SV(elt, list)
#define UTLIST_NEXT(elt, list, next) ((elt)->next)
#define UTLIST_NEXTASGN(elt, list, to, next) ((elt)->next) = (to)
/* #define UTLIST_PREV(elt,list,prev) ((elt)->prev) */
#define UTLIST_PREVASGN(elt, list, to, prev) ((elt)->prev) = (to)
#define UTLIST_RS(list)
#define UTLIST_CASTASGN(a, b) (a) = (b)
#endif

/******************************************************************************
 * The sort macro is an adaptation of Simon Tatham's O(n log(n)) mergesort    *
 * Unwieldy variable names used here to avoid shadowing passed-in variables.  *
 *****************************************************************************/
#define LL_SORT(list, cmp) LL_SORT2(list, cmp, next)

#define LL_SORT2(list, cmp, next)                                                                  \
	do {                                                                                           \
		LDECLTYPE(list) _ls_p;                                                                     \
		LDECLTYPE(list) _ls_q;                                                                     \
		LDECLTYPE(list) _ls_e;                                                                     \
		LDECLTYPE(list) _ls_tail;                                                                  \
		IF_NO_DECLTYPE(LDECLTYPE(list) _tmp;)                                                      \
		int _ls_insize, _ls_nmerges, _ls_psize, _ls_qsize, _ls_i, _ls_looping;                     \
		if (list) {                                                                                \
			_ls_insize = 1;                                                                        \
			_ls_looping = 1;                                                                       \
			while (_ls_looping) {                                                                  \
				UTLIST_CASTASGN(_ls_p, list);                                                      \
				(list) = NULL;                                                                     \
				_ls_tail = NULL;                                                                   \
				_ls_nmerges = 0;                                                                   \
				while (_ls_p) {                                                                    \
					_ls_nmerges++;                                                                 \
					_ls_q = _ls_p;                                                                 \
					_ls_psize = 0;                                                                 \
					for (_ls_i = 0; _ls_i < _ls_insize; _ls_i++) {                                 \
						_ls_psize++;                                                               \
						UTLIST_SV(_ls_q, list);                                                    \
						_ls_q = UTLIST_NEXT(_ls_q, list, next);                                    \
						UTLIST_RS(list);                                                           \
						if (!_ls_q)                                                                \
							break;                                                                 \
					}                                                                              \
					_ls_qsize = _ls_insize;                                                        \
					while (_ls_psize > 0 || (_ls_qsize > 0 && _ls_q)) {                            \
						if (_ls_psize == 0) {                                                      \
							_ls_e = _ls_q;                                                         \
							UTLIST_SV(_ls_q, list);                                                \
							_ls_q = UTLIST_NEXT(_ls_q, list, next);                                \
							UTLIST_RS(list);                                                       \
							_ls_qsize--;                                                           \
						} else if (_ls_qsize == 0 || !_ls_q) {                                     \
							_ls_e = _ls_p;                                                         \
							UTLIST_SV(_ls_p, list);                                                \
							_ls_p = UTLIST_NEXT(_ls_p, list, next);                                \
							UTLIST_RS(list);                                                       \
							_ls_psize--;                                                           \
						} else if (cmp(_ls_p, _ls_q) <= 0) {                                       \
							_ls_e = _ls_p;                                                         \
							UTLIST_SV(_ls_p, list);                                                \
							_ls_p = UTLIST_NEXT(_ls_p, list, next);                                \
							UTLIST_RS(list);                                                       \
							_ls_psize--;                                                           \
						} else {                                                                   \
							_ls_e = _ls_q;                                                         \
							UTLIST_SV(_ls_q, list);                                                \
							_ls_q = UTLIST_NEXT(_ls_q, list, next);                                \
							UTLIST_RS(list);                                                       \
							_ls_qsize--;                                                           \
						}                                                                          \
						if (_ls_tail) {                                                            \
							UTLIST_SV(_ls_tail, list);                                             \
							UTLIST_NEXTASGN(_ls_tail, list, _ls_e, next);                          \
							UTLIST_RS(list);                                                       \
						} else {                                                                   \
							UTLIST_CASTASGN(list, _ls_e);                                          \
						}                                                                          \
						_ls_tail = _ls_e;                                                          \
					}                                                                              \
					_ls_p = _ls_q;                                                                 \
				}                                                                                  \
				if (_ls_tail) {                                                                    \
					UTLIST_SV(_ls_tail, list);                                                     \
					UTLIST_NEXTASGN(_ls_tail, list, NULL, next);                                   \
					UTLIST_RS(list);                                                               \
				}                                                                                  \
				if (_ls_nmerges <= 1) {                                                            \
					_ls_looping = 0;                                                               \
				}                                                                                  \
				_ls_insize *= 2;                                                                   \
			}                                                                                      \
		}                                                                                          \
	} while (0)

#define DL_SORT(list, cmp) DL_SORT2(list, cmp, prev, next)

#define DL_SORT2(list, cmp, prev, next)                                                            \
	do {                                                                                           \
		LDECLTYPE(list) _ls_p;                                                                     \
		LDECLTYPE(list) _ls_q;                                                                     \
		LDECLTYPE(list) _ls_e;                                                                     \
		LDECLTYPE(list) _ls_tail;                                                                  \
		IF_NO_DECLTYPE(LDECLTYPE(list) _tmp;)                                                      \
		int _ls_insize, _ls_nmerges, _ls_psize, _ls_qsize, _ls_i, _ls_looping;                     \
		if (list) {                                                                                \
			_ls_insize = 1;                                                                        \
			_ls_looping = 1;                                                                       \
			while (_ls_looping) {                                                                  \
				UTLIST_CASTASGN(_ls_p, list);                                                      \
				(list) = NULL;                                                                     \
				_ls_tail = NULL;                                                                   \
				_ls_nmerges = 0;                                                                   \
				while (_ls_p) {                                                                    \
					_ls_nmerges++;                                                                 \
					_ls_q = _ls_p;                                                                 \
					_ls_psize = 0;                                                                 \
					for (_ls_i = 0; _ls_i < _ls_insize; _ls_i++) {                                 \
						_ls_psize++;                                                               \
						UTLIST_SV(_ls_q, list);                                                    \
						_ls_q = UTLIST_NEXT(_ls_q, list, next);                                    \
						UTLIST_RS(list);                                                           \
						if (!_ls_q)                                                                \
							break;                                                                 \
					}                                                                              \
					_ls_qsize = _ls_insize;                                                        \
					while ((_ls_psize > 0) || ((_ls_qsize > 0) && _ls_q)) {                        \
						if (_ls_psize == 0) {                                                      \
							_ls_e = _ls_q;                                                         \
							UTLIST_SV(_ls_q, list);                                                \
							_ls_q = UTLIST_NEXT(_ls_q, list, next);                                \
							UTLIST_RS(list);                                                       \
							_ls_qsize--;                                                           \
						} else if ((_ls_qsize == 0) || (!_ls_q)) {                                 \
							_ls_e = _ls_p;                                                         \
							UTLIST_SV(_ls_p, list);                                                \
							_ls_p = UTLIST_NEXT(_ls_p, list, next);                                \
							UTLIST_RS(list);                                                       \
							_ls_psize--;                                                           \
						} else if (cmp(_ls_p, _ls_q) <= 0) {                                       \
							_ls_e = _ls_p;                                                         \
							UTLIST_SV(_ls_p, list);                                                \
							_ls_p = UTLIST_NEXT(_ls_p, list, next);                                \
							UTLIST_RS(list);                                                       \
							_ls_psize--;                                                           \
						} else {                                                                   \
							_ls_e = _ls_q;                                                         \
							UTLIST_SV(_ls_q, list);                                                \
							_ls_q = UTLIST_NEXT(_ls_q, list, next);                                \
							UTLIST_RS(list);                                                       \
							_ls_qsize--;                                                           \
						}                                                                          \
						if (_ls_tail) {                                                            \
							UTLIST_SV(_ls_tail, list);                                             \
							UTLIST_NEXTASGN(_ls_tail, list, _ls_e, next);                          \
							UTLIST_RS(list);                                                       \
						} else {                                                                   \
							UTLIST_CASTASGN(list, _ls_e);                                          \
						}                                                                          \
						UTLIST_SV(_ls_e, list);                                                    \
						UTLIST_PREVASGN(_ls_e, list, _ls_tail, prev);                              \
						UTLIST_RS(list);                                                           \
						_ls_tail = _ls_e;                                                          \
					}                                                                              \
					_ls_p = _ls_q;                                                                 \
				}                                                                                  \
				UTLIST_CASTASGN((list)->prev, _ls_tail);                                           \
				UTLIST_SV(_ls_tail, list);                                                         \
				UTLIST_NEXTASGN(_ls_tail, list, NULL, next);                                       \
				UTLIST_RS(list);                                                                   \
				if (_ls_nmerges <= 1) {                                                            \
					_ls_looping = 0;                                                               \
				}                                                                                  \
				_ls_insize *= 2;                                                                   \
			}                                                                                      \
		}                                                                                          \
	} while (0)

#define CDL_SORT(list, cmp) CDL_SORT2(list, cmp, prev, next)

#define CDL_SORT2(list, cmp, prev, next)                                                           \
	do {                                                                                           \
		LDECLTYPE(list) _ls_p;                                                                     \
		LDECLTYPE(list) _ls_q;                                                                     \
		LDECLTYPE(list) _ls_e;                                                                     \
		LDECLTYPE(list) _ls_tail;                                                                  \
		LDECLTYPE(list) _ls_oldhead;                                                               \
		LDECLTYPE(list) _tmp;                                                                      \
		int _ls_insize, _ls_nmerges, _ls_psize, _ls_qsize, _ls_i, _ls_looping;                     \
		if (list) {                                                                                \
			_ls_insize = 1;                                                                        \
			_ls_looping = 1;                                                                       \
			while (_ls_looping) {                                                                  \
				UTLIST_CASTASGN(_ls_p, list);                                                      \
				UTLIST_CASTASGN(_ls_oldhead, list);                                                \
				(list) = NULL;                                                                     \
				_ls_tail = NULL;                                                                   \
				_ls_nmerges = 0;                                                                   \
				while (_ls_p) {                                                                    \
					_ls_nmerges++;                                                                 \
					_ls_q = _ls_p;                                                                 \
					_ls_psize = 0;                                                                 \
					for (_ls_i = 0; _ls_i < _ls_insize; _ls_i++) {                                 \
						_ls_psize++;                                                               \
						UTLIST_SV(_ls_q, list);                                                    \
						if (UTLIST_NEXT(_ls_q, list, next) == _ls_oldhead) {                       \
							_ls_q = NULL;                                                          \
						} else {                                                                   \
							_ls_q = UTLIST_NEXT(_ls_q, list, next);                                \
						}                                                                          \
						UTLIST_RS(list);                                                           \
						if (!_ls_q)                                                                \
							break;                                                                 \
					}                                                                              \
					_ls_qsize = _ls_insize;                                                        \
					while (_ls_psize > 0 || (_ls_qsize > 0 && _ls_q)) {                            \
						if (_ls_psize == 0) {                                                      \
							_ls_e = _ls_q;                                                         \
							UTLIST_SV(_ls_q, list);                                                \
							_ls_q = UTLIST_NEXT(_ls_q, list, next);                                \
							UTLIST_RS(list);                                                       \
							_ls_qsize--;                                                           \
							if (_ls_q == _ls_oldhead) {                                            \
								_ls_q = NULL;                                                      \
							}                                                                      \
						} else if (_ls_qsize == 0 || !_ls_q) {                                     \
							_ls_e = _ls_p;                                                         \
							UTLIST_SV(_ls_p, list);                                                \
							_ls_p = UTLIST_NEXT(_ls_p, list, next);                                \
							UTLIST_RS(list);                                                       \
							_ls_psize--;                                                           \
							if (_ls_p == _ls_oldhead) {                                            \
								_ls_p = NULL;                                                      \
							}                                                                      \
						} else if (cmp(_ls_p, _ls_q) <= 0) {                                       \
							_ls_e = _ls_p;                                                         \
							UTLIST_SV(_ls_p, list);                                                \
							_ls_p = UTLIST_NEXT(_ls_p, list, next);                                \
							UTLIST_RS(list);                                                       \
							_ls_psize--;                                                           \
							if (_ls_p == _ls_oldhead) {                                            \
								_ls_p = NULL;                                                      \
							}                                                                      \
						} else {                                                                   \
							_ls_e = _ls_q;                                                         \
							UTLIST_SV(_ls_q, list);                                                \
							_ls_q = UTLIST_NEXT(_ls_q, list, next);                                \
							UTLIST_RS(list);                                                       \
							_ls_qsize--;                                                           \
							if (_ls_q == _ls_oldhead) {                                            \
								_ls_q = NULL;                                                      \
							}                                                                      \
						}                                                                          \
						if (_ls_tail) {                                                            \
							UTLIST_SV(_ls_tail, list);                                             \
							UTLIST_NEXTASGN(_ls_tail, list, _ls_e, next);                          \
							UTLIST_RS(list);                                                       \
						} else {                                                                   \
							UTLIST_CASTASGN(list, _ls_e);                                          \
						}                                                                          \
						UTLIST_SV(_ls_e, list);                                                    \
						UTLIST_PREVASGN(_ls_e, list, _ls_tail, prev);                              \
						UTLIST_RS(list);                                                           \
						_ls_tail = _ls_e;                                                          \
					}                                                                              \
					_ls_p = _ls_q;                                                                 \
				}                                                                                  \
				UTLIST_CASTASGN((list)->prev, _ls_tail);                                           \
				UTLIST_CASTASGN(_tmp, list);                                                       \
				UTLIST_SV(_ls_tail, list);                                                         \
				UTLIST_NEXTASGN(_ls_tail, list, _tmp, next);                                       \
				UTLIST_RS(list);                                                                   \
				if (_ls_nmerges <= 1) {                                                            \
					_ls_looping = 0;                                                               \
				}                                                                                  \
				_ls_insize *= 2;                                                                   \
			}                                                                                      \
		}                                                                                          \
	} while (0)

/******************************************************************************
 * singly linked list macros (non-circular)                                   *
 *****************************************************************************/
#define LL_PREPEND(head, add) LL_PREPEND2(head, add, next)

#define LL_PREPEND2(head, add, next)                                                               \
	do {                                                                                           \
		(add)->next = (head);                                                                      \
		(head) = (add);                                                                            \
	} while (0)

#define LL_CONCAT(head1, head2) LL_CONCAT2(head1, head2, next)

#define LL_CONCAT2(head1, head2, next)                                                             \
	do {                                                                                           \
		LDECLTYPE(head1) _tmp;                                                                     \
		if (head1) {                                                                               \
			_tmp = (head1);                                                                        \
			while (_tmp->next) {                                                                   \
				_tmp = _tmp->next;                                                                 \
			}                                                                                      \
			_tmp->next = (head2);                                                                  \
		} else {                                                                                   \
			(head1) = (head2);                                                                     \
		}                                                                                          \
	} while (0)

#define LL_APPEND(head, add) LL_APPEND2(head, add, next)

#define LL_APPEND2(head, add, next)                                                                \
	do {                                                                                           \
		LDECLTYPE(head) _tmp;                                                                      \
		(add)->next = NULL;                                                                        \
		if (head) {                                                                                \
			_tmp = (head);                                                                         \
			while (_tmp->next) {                                                                   \
				_tmp = _tmp->next;                                                                 \
			}                                                                                      \
			_tmp->next = (add);                                                                    \
		} else {                                                                                   \
			(head) = (add);                                                                        \
		}                                                                                          \
	} while (0)

#define LL_INSERT_INORDER(head, add, cmp) LL_INSERT_INORDER2(head, add, cmp, next)

#define LL_INSERT_INORDER2(head, add, cmp, next)                                                   \
	do {                                                                                           \
		LDECLTYPE(head) _tmp;                                                                      \
		if (head) {                                                                                \
			LL_LOWER_BOUND(head, _tmp, add, cmp);                                                  \
			LL_APPEND_ELEM(head, _tmp, add);                                                       \
		} else {                                                                                   \
			(head) = (add);                                                                        \
			(head)->next = NULL;                                                                   \
		}                                                                                          \
	} while (0)

#define LL_LOWER_BOUND(head, elt, like, cmp) LL_LOWER_BOUND2(head, elt, like, cmp, next)

#define LL_LOWER_BOUND2(head, elt, like, cmp, next)                                                \
	do {                                                                                           \
		if ((head) == NULL || (cmp(head, like)) >= 0) {                                            \
			(elt) = NULL;                                                                          \
		} else {                                                                                   \
			for ((elt) = (head); (elt)->next != NULL; (elt) = (elt)->next) {                       \
				if (cmp((elt)->next, like) >= 0) {                                                 \
					break;                                                                         \
				}                                                                                  \
			}                                                                                      \
		}                                                                                          \
	} while (0)

#define LL_DELETE(head, del) LL_DELETE2(head, del, next)

#define LL_DELETE2(head, del, next)                                                                \
	do {                                                                                           \
		LDECLTYPE(head) _tmp;                                                                      \
		if ((head) == (del)) {                                                                     \
			(head) = (head)->next;                                                                 \
		} else {                                                                                   \
			_tmp = (head);                                                                         \
			while (_tmp->next && (_tmp->next != (del))) {                                          \
				_tmp = _tmp->next;                                                                 \
			}                                                                                      \
			if (_tmp->next) {                                                                      \
				_tmp->next = (del)->next;                                                          \
			}                                                                                      \
		}                                                                                          \
	} while (0)

#define LL_COUNT(head, el, counter) LL_COUNT2(head, el, counter, next)

#define LL_COUNT2(head, el, counter, next)                                                         \
	do {                                                                                           \
		(counter) = 0;                                                                             \
		LL_FOREACH2(head, el, next) { ++(counter); }                                               \
	} while (0)

#define LL_FOREACH(head, el) LL_FOREACH2(head, el, next)

#define LL_FOREACH2(head, el, next) for ((el) = (head); el; (el) = (el)->next)

#define LL_FOREACH_SAFE(head, el, tmp) LL_FOREACH_SAFE2(head, el, tmp, next)

#define LL_FOREACH_SAFE2(head, el, tmp, next)                                                      \
	for ((el) = (head); (el) && ((tmp) = (el)->next, 1); (el) = (tmp))

#define LL_SEARCH_SCALAR(head, out, field, val) LL_SEARCH_SCALAR2(head, out, field, val, next)

#define LL_SEARCH_SCALAR2(head, out, field, val, next)                                             \
	do {                                                                                           \
		LL_FOREACH2(head, out, next) {                                                             \
			if ((out)->field == (val))                                                             \
				break;                                                                             \
		}                                                                                          \
	} while (0)

#define LL_SEARCH(head, out, elt, cmp) LL_SEARCH2(head, out, elt, cmp, next)

#define LL_SEARCH2(head, out, elt, cmp, next)                                                      \
	do {                                                                                           \
		LL_FOREACH2(head, out, next) {                                                             \
			if ((cmp(out, elt)) == 0)                                                              \
				break;                                                                             \
		}                                                                                          \
	} while (0)

#define LL_REPLACE_ELEM2(head, el, add, next)                                                      \
	do {                                                                                           \
		LDECLTYPE(head) _tmp;                                                                      \
		assert((head) != NULL);                                                                    \
		assert((el) != NULL);                                                                      \
		assert((add) != NULL);                                                                     \
		(add)->next = (el)->next;                                                                  \
		if ((head) == (el)) {                                                                      \
			(head) = (add);                                                                        \
		} else {                                                                                   \
			_tmp = (head);                                                                         \
			while (_tmp->next && (_tmp->next != (el))) {                                           \
				_tmp = _tmp->next;                                                                 \
			}                                                                                      \
			if (_tmp->next) {                                                                      \
				_tmp->next = (add);                                                                \
			}                                                                                      \
		}                                                                                          \
	} while (0)

#define LL_REPLACE_ELEM(head, el, add) LL_REPLACE_ELEM2(head, el, add, next)

#define LL_PREPEND_ELEM2(head, el, add, next)                                                      \
	do {                                                                                           \
		if (el) {                                                                                  \
			LDECLTYPE(head) _tmp;                                                                  \
			assert((head) != NULL);                                                                \
			assert((add) != NULL);                                                                 \
			(add)->next = (el);                                                                    \
			if ((head) == (el)) {                                                                  \
				(head) = (add);                                                                    \
			} else {                                                                               \
				_tmp = (head);                                                                     \
				while (_tmp->next && (_tmp->next != (el))) {                                       \
					_tmp = _tmp->next;                                                             \
				}                                                                                  \
				if (_tmp->next) {                                                                  \
					_tmp->next = (add);                                                            \
				}                                                                                  \
			}                                                                                      \
		} else {                                                                                   \
			LL_APPEND2(head, add, next);                                                           \
		}                                                                                          \
	} while (0)

#define LL_PREPEND_ELEM(head, el, add) LL_PREPEND_ELEM2(head, el, add, next)

#define LL_APPEND_ELEM2(head, el, add, next)                                                       \
	do {                                                                                           \
		if (el) {                                                                                  \
			assert((head) != NULL);                                                                \
			assert((add) != NULL);                                                                 \
			(add)->next = (el)->next;                                                              \
			(el)->next = (add);                                                                    \
		} else {                                                                                   \
			LL_PREPEND2(head, add, next);                                                          \
		}                                                                                          \
	} while (0)

#define LL_APPEND_ELEM(head, el, add) LL_APPEND_ELEM2(head, el, add, next)

#ifdef NO_DECLTYPE
/* Here are VS2008 / NO_DECLTYPE replacements for a few functions */

#undef LL_CONCAT2
#define LL_CONCAT2(head1, head2, next)                                                             \
	do {                                                                                           \
		char *_tmp;                                                                                \
		if (head1) {                                                                               \
			_tmp = (char *)(head1);                                                                \
			while ((head1)->next) {                                                                \
				(head1) = (head1)->next;                                                           \
			}                                                                                      \
			(head1)->next = (head2);                                                               \
			UTLIST_RS(head1);                                                                      \
		} else {                                                                                   \
			(head1) = (head2);                                                                     \
		}                                                                                          \
	} while (0)

#undef LL_APPEND2
#define LL_APPEND2(head, add, next)                                                                \
	do {                                                                                           \
		if (head) {                                                                                \
			(add)->next = head; /* use add->next as a temp variable */                             \
			while ((add)->next->next) {                                                            \
				(add)->next = (add)->next->next;                                                   \
			}                                                                                      \
			(add)->next->next = (add);                                                             \
		} else {                                                                                   \
			(head) = (add);                                                                        \
		}                                                                                          \
		(add)->next = NULL;                                                                        \
	} while (0)

#undef LL_INSERT_INORDER2
#define LL_INSERT_INORDER2(head, add, cmp, next)                                                   \
	do {                                                                                           \
		if ((head) == NULL || (cmp(head, add)) >= 0) {                                             \
			(add)->next = (head);                                                                  \
			(head) = (add);                                                                        \
		} else {                                                                                   \
			char *_tmp = (char *)(head);                                                           \
			while ((head)->next != NULL && (cmp((head)->next, add)) < 0) {                         \
				(head) = (head)->next;                                                             \
			}                                                                                      \
			(add)->next = (head)->next;                                                            \
			(head)->next = (add);                                                                  \
			UTLIST_RS(head);                                                                       \
		}                                                                                          \
	} while (0)

#undef LL_DELETE2
#define LL_DELETE2(head, del, next)                                                                \
	do {                                                                                           \
		if ((head) == (del)) {                                                                     \
			(head) = (head)->next;                                                                 \
		} else {                                                                                   \
			char *_tmp = (char *)(head);                                                           \
			while ((head)->next && ((head)->next != (del))) {                                      \
				(head) = (head)->next;                                                             \
			}                                                                                      \
			if ((head)->next) {                                                                    \
				(head)->next = ((del)->next);                                                      \
			}                                                                                      \
			UTLIST_RS(head);                                                                       \
		}                                                                                          \
	} while (0)

#undef LL_REPLACE_ELEM2
#define LL_REPLACE_ELEM2(head, el, add, next)                                                      \
	do {                                                                                           \
		assert((head) != NULL);                                                                    \
		assert((el) != NULL);                                                                      \
		assert((add) != NULL);                                                                     \
		if ((head) == (el)) {                                                                      \
			(head) = (add);                                                                        \
		} else {                                                                                   \
			(add)->next = head;                                                                    \
			while ((add)->next->next && ((add)->next->next != (el))) {                             \
				(add)->next = (add)->next->next;                                                   \
			}                                                                                      \
			if ((add)->next->next) {                                                               \
				(add)->next->next = (add);                                                         \
			}                                                                                      \
		}                                                                                          \
		(add)->next = (el)->next;                                                                  \
	} while (0)

#undef LL_PREPEND_ELEM2
#define LL_PREPEND_ELEM2(head, el, add, next)                                                      \
	do {                                                                                           \
		if (el) {                                                                                  \
			assert((head) != NULL);                                                                \
			assert((add) != NULL);                                                                 \
			if ((head) == (el)) {                                                                  \
				(head) = (add);                                                                    \
			} else {                                                                               \
				(add)->next = (head);                                                              \
				while ((add)->next->next && ((add)->next->next != (el))) {                         \
					(add)->next = (add)->next->next;                                               \
				}                                                                                  \
				if ((add)->next->next) {                                                           \
					(add)->next->next = (add);                                                     \
				}                                                                                  \
			}                                                                                      \
			(add)->next = (el);                                                                    \
		} else {                                                                                   \
			LL_APPEND2(head, add, next);                                                           \
		}                                                                                          \
	} while (0)

#endif /* NO_DECLTYPE */

/******************************************************************************
 * doubly linked list macros (non-circular)                                   *
 *****************************************************************************/
#define DL_PREPEND(head, add) DL_PREPEND2(head, add, prev, next)

#define DL_PREPEND2(head, add, prev, next)                                                         \
	do {                                                                                           \
		(add)->next = (head);                                                                      \
		if (head) {                                                                                \
			(add)->prev = (head)->prev;                                                            \
			(head)->prev = (add);                                                                  \
		} else {                                                                                   \
			(add)->prev = (add);                                                                   \
		}                                                                                          \
		(head) = (add);                                                                            \
	} while (0)

#define DL_APPEND(head, add) DL_APPEND2(head, add, prev, next)

#define DL_APPEND2(head, add, prev, next)                                                          \
	do {                                                                                           \
		if (head) {                                                                                \
			(add)->prev = (head)->prev;                                                            \
			(head)->prev->next = (add);                                                            \
			(head)->prev = (add);                                                                  \
			(add)->next = NULL;                                                                    \
		} else {                                                                                   \
			(head) = (add);                                                                        \
			(head)->prev = (head);                                                                 \
			(head)->next = NULL;                                                                   \
		}                                                                                          \
	} while (0)

#define DL_INSERT_INORDER(head, add, cmp) DL_INSERT_INORDER2(head, add, cmp, next)

#define DL_INSERT_INORDER2(head, add, cmp, next)                                                   \
	do {                                                                                           \
		LDECLTYPE(head) _tmp;                                                                      \
		if (head) {                                                                                \
			DL_LOWER_BOUND(head, _tmp, add, cmp);                                                  \
			DL_APPEND_ELEM(head, _tmp, add);                                                       \
		} else {                                                                                   \
			(head) = (add);                                                                        \
			(head)->prev = (head);                                                                 \
			(head)->next = NULL;                                                                   \
		}                                                                                          \
	} while (0)

#define DL_LOWER_BOUND(head, elt, like, cmp) DL_LOWER_BOUND2(head, elt, like, cmp, next)

#define DL_LOWER_BOUND2(head, elt, like, cmp, next)                                                \
	do {                                                                                           \
		if ((head) == NULL || (cmp(head, like)) >= 0) {                                            \
			(elt) = NULL;                                                                          \
		} else {                                                                                   \
			for ((elt) = (head); (elt)->next != NULL; (elt) = (elt)->next) {                       \
				if ((cmp((elt)->next, like)) >= 0) {                                               \
					break;                                                                         \
				}                                                                                  \
			}                                                                                      \
		}                                                                                          \
	} while (0)

#define DL_CONCAT(head1, head2) DL_CONCAT2(head1, head2, prev, next)

#define DL_CONCAT2(head1, head2, prev, next)                                                       \
	do {                                                                                           \
		LDECLTYPE(head1) _tmp;                                                                     \
		if (head2) {                                                                               \
			if (head1) {                                                                           \
				UTLIST_CASTASGN(_tmp, (head2)->prev);                                              \
				(head2)->prev = (head1)->prev;                                                     \
				(head1)->prev->next = (head2);                                                     \
				UTLIST_CASTASGN((head1)->prev, _tmp);                                              \
			} else {                                                                               \
				(head1) = (head2);                                                                 \
			}                                                                                      \
		}                                                                                          \
	} while (0)

#define DL_DELETE(head, del) DL_DELETE2(head, del, prev, next)

#define DL_DELETE2(head, del, prev, next)                                                          \
	do {                                                                                           \
		assert((head) != NULL);                                                                    \
		assert((del)->prev != NULL);                                                               \
		if ((del)->prev == (del)) {                                                                \
			(head) = NULL;                                                                         \
		} else if ((del) == (head)) {                                                              \
			(del)->next->prev = (del)->prev;                                                       \
			(head) = (del)->next;                                                                  \
		} else {                                                                                   \
			(del)->prev->next = (del)->next;                                                       \
			if ((del)->next) {                                                                     \
				(del)->next->prev = (del)->prev;                                                   \
			} else {                                                                               \
				(head)->prev = (del)->prev;                                                        \
			}                                                                                      \
		}                                                                                          \
	} while (0)

#define DL_COUNT(head, el, counter) DL_COUNT2(head, el, counter, next)

#define DL_COUNT2(head, el, counter, next)                                                         \
	do {                                                                                           \
		(counter) = 0;                                                                             \
		DL_FOREACH2(head, el, next) { ++(counter); }                                               \
	} while (0)

#define DL_FOREACH(head, el) DL_FOREACH2(head, el, next)

#define DL_FOREACH2(head, el, next) for ((el) = (head); el; (el) = (el)->next)

/* this version is safe for deleting the elements during iteration */
#define DL_FOREACH_SAFE(head, el, tmp) DL_FOREACH_SAFE2(head, el, tmp, next)

#define DL_FOREACH_SAFE2(head, el, tmp, next)                                                      \
	for ((el) = (head); (el) && ((tmp) = (el)->next, 1); (el) = (tmp))

/* these are identical to their singly-linked list counterparts */
#define DL_SEARCH_SCALAR LL_SEARCH_SCALAR
#define DL_SEARCH LL_SEARCH
#define DL_SEARCH_SCALAR2 LL_SEARCH_SCALAR2
#define DL_SEARCH2 LL_SEARCH2

#define DL_REPLACE_ELEM2(head, el, add, prev, next)                                                \
	do {                                                                                           \
		assert((head) != NULL);                                                                    \
		assert((el) != NULL);                                                                      \
		assert((add) != NULL);                                                                     \
		if ((head) == (el)) {                                                                      \
			(head) = (add);                                                                        \
			(add)->next = (el)->next;                                                              \
			if ((el)->next == NULL) {                                                              \
				(add)->prev = (add);                                                               \
			} else {                                                                               \
				(add)->prev = (el)->prev;                                                          \
				(add)->next->prev = (add);                                                         \
			}                                                                                      \
		} else {                                                                                   \
			(add)->next = (el)->next;                                                              \
			(add)->prev = (el)->prev;                                                              \
			(add)->prev->next = (add);                                                             \
			if ((el)->next == NULL) {                                                              \
				(head)->prev = (add);                                                              \
			} else {                                                                               \
				(add)->next->prev = (add);                                                         \
			}                                                                                      \
		}                                                                                          \
	} while (0)

#define DL_REPLACE_ELEM(head, el, add) DL_REPLACE_ELEM2(head, el, add, prev, next)

#define DL_PREPEND_ELEM2(head, el, add, prev, next)                                                \
	do {                                                                                           \
		if (el) {                                                                                  \
			assert((head) != NULL);                                                                \
			assert((add) != NULL);                                                                 \
			(add)->next = (el);                                                                    \
			(add)->prev = (el)->prev;                                                              \
			(el)->prev = (add);                                                                    \
			if ((head) == (el)) {                                                                  \
				(head) = (add);                                                                    \
			} else {                                                                               \
				(add)->prev->next = (add);                                                         \
			}                                                                                      \
		} else {                                                                                   \
			DL_APPEND2(head, add, prev, next);                                                     \
		}                                                                                          \
	} while (0)

#define DL_PREPEND_ELEM(head, el, add) DL_PREPEND_ELEM2(head, el, add, prev, next)

#define DL_APPEND_ELEM2(head, el, add, prev, next)                                                 \
	do {                                                                                           \
		if (el) {                                                                                  \
			assert((head) != NULL);                                                                \
			assert((add) != NULL);                                                                 \
			(add)->next = (el)->next;                                                              \
			(add)->prev = (el);                                                                    \
			(el)->next = (add);                                                                    \
			if ((add)->next) {                                                                     \
				(add)->next->prev = (add);                                                         \
			} else {                                                                               \
				(head)->prev = (add);                                                              \
			}                                                                                      \
		} else {                                                                                   \
			DL_PREPEND2(head, add, prev, next);                                                    \
		}                                                                                          \
	} while (0)

#define DL_APPEND_ELEM(head, el, add) DL_APPEND_ELEM2(head, el, add, prev, next)

#ifdef NO_DECLTYPE
/* Here are VS2008 / NO_DECLTYPE replacements for a few functions */

#undef DL_INSERT_INORDER2
#define DL_INSERT_INORDER2(head, add, cmp, next)                                                   \
	do {                                                                                           \
		if ((head) == NULL) {                                                                      \
			(add)->prev = (add);                                                                   \
			(add)->next = NULL;                                                                    \
			(head) = (add);                                                                        \
		} else if ((cmp(head, add)) >= 0) {                                                        \
			(add)->prev = (head)->prev;                                                            \
			(add)->next = (head);                                                                  \
			(head)->prev = (add);                                                                  \
			(head) = (add);                                                                        \
		} else {                                                                                   \
			char *_tmp = (char *)(head);                                                           \
			while ((char *)(head)->next != _tmp && (cmp((head)->next, add)) < 0) {                 \
				(head) = (head)->next;                                                             \
			}                                                                                      \
			(add)->prev = (head);                                                                  \
			(add)->next = (head)->next;                                                            \
			(head)->next = (add);                                                                  \
			UTLIST_RS(head);                                                                       \
			if ((add)->next) {                                                                     \
				(add)->next->prev = (add);                                                         \
			} else {                                                                               \
				(head)->prev = (add);                                                              \
			}                                                                                      \
		}                                                                                          \
	} while (0)
#endif /* NO_DECLTYPE */

/******************************************************************************
 * circular doubly linked list macros                                         *
 *****************************************************************************/
#define CDL_APPEND(head, add) CDL_APPEND2(head, add, prev, next)

#define CDL_APPEND2(head, add, prev, next)                                                         \
	do {                                                                                           \
		if (head) {                                                                                \
			(add)->prev = (head)->prev;                                                            \
			(add)->next = (head);                                                                  \
			(head)->prev = (add);                                                                  \
			(add)->prev->next = (add);                                                             \
		} else {                                                                                   \
			(add)->prev = (add);                                                                   \
			(add)->next = (add);                                                                   \
			(head) = (add);                                                                        \
		}                                                                                          \
	} while (0)

#define CDL_PREPEND(head, add) CDL_PREPEND2(head, add, prev, next)

#define CDL_PREPEND2(head, add, prev, next)                                                        \
	do {                                                                                           \
		if (head) {                                                                                \
			(add)->prev = (head)->prev;                                                            \
			(add)->next = (head);                                                                  \
			(head)->prev = (add);                                                                  \
			(add)->prev->next = (add);                                                             \
		} else {                                                                                   \
			(add)->prev = (add);                                                                   \
			(add)->next = (add);                                                                   \
		}                                                                                          \
		(head) = (add);                                                                            \
	} while (0)

#define CDL_INSERT_INORDER(head, add, cmp) CDL_INSERT_INORDER2(head, add, cmp, next)

#define CDL_INSERT_INORDER2(head, add, cmp, next)                                                  \
	do {                                                                                           \
		LDECLTYPE(head) _tmp;                                                                      \
		if (head) {                                                                                \
			CDL_LOWER_BOUND(head, _tmp, add, cmp);                                                 \
			CDL_APPEND_ELEM(head, _tmp, add);                                                      \
		} else {                                                                                   \
			(head) = (add);                                                                        \
			(head)->next = (head);                                                                 \
			(head)->prev = (head);                                                                 \
		}                                                                                          \
	} while (0)

#define CDL_LOWER_BOUND(head, elt, like, cmp) CDL_LOWER_BOUND2(head, elt, like, cmp, next)

#define CDL_LOWER_BOUND2(head, elt, like, cmp, next)                                               \
	do {                                                                                           \
		if ((head) == NULL || (cmp(head, like)) >= 0) {                                            \
			(elt) = NULL;                                                                          \
		} else {                                                                                   \
			for ((elt) = (head); (elt)->next != (head); (elt) = (elt)->next) {                     \
				if ((cmp((elt)->next, like)) >= 0) {                                               \
					break;                                                                         \
				}                                                                                  \
			}                                                                                      \
		}                                                                                          \
	} while (0)

#define CDL_DELETE(head, del) CDL_DELETE2(head, del, prev, next)

#define CDL_DELETE2(head, del, prev, next)                                                         \
	do {                                                                                           \
		if (((head) == (del)) && ((head)->next == (head))) {                                       \
			(head) = NULL;                                                                         \
		} else {                                                                                   \
			(del)->next->prev = (del)->prev;                                                       \
			(del)->prev->next = (del)->next;                                                       \
			if ((del) == (head))                                                                   \
				(head) = (del)->next;                                                              \
		}                                                                                          \
	} while (0)

#define CDL_COUNT(head, el, counter) CDL_COUNT2(head, el, counter, next)

#define CDL_COUNT2(head, el, counter, next)                                                        \
	do {                                                                                           \
		(counter) = 0;                                                                             \
		CDL_FOREACH2(head, el, next) { ++(counter); }                                              \
	} while (0)

#define CDL_FOREACH(head, el) CDL_FOREACH2(head, el, next)

#define CDL_FOREACH2(head, el, next)                                                               \
	for ((el) = (head); el; (el) = (((el)->next == (head)) ? NULL : (el)->next))

#define CDL_FOREACH_SAFE(head, el, tmp1, tmp2) CDL_FOREACH_SAFE2(head, el, tmp1, tmp2, prev, next)

#define CDL_FOREACH_SAFE2(head, el, tmp1, tmp2, prev, next)                                        \
	for ((el) = (head), (tmp1) = (head) ? (head)->prev : NULL; (el) && ((tmp2) = (el)->next, 1);   \
	     (el) = ((el) == (tmp1) ? NULL : (tmp2)))

#define CDL_SEARCH_SCALAR(head, out, field, val) CDL_SEARCH_SCALAR2(head, out, field, val, next)

#define CDL_SEARCH_SCALAR2(head, out, field, val, next)                                            \
	do {                                                                                           \
		CDL_FOREACH2(head, out, next) {                                                            \
			if ((out)->field == (val))                                                             \
				break;                                                                             \
		}                                                                                          \
	} while (0)

#define CDL_SEARCH(head, out, elt, cmp) CDL_SEARCH2(head, out, elt, cmp, next)

#define CDL_SEARCH2(head, out, elt, cmp, next)                                                     \
	do {                                                                                           \
		CDL_FOREACH2(head, out, next) {                                                            \
			if ((cmp(out, elt)) == 0)                                                              \
				break;                                                                             \
		}                                                                                          \
	} while (0)

#define CDL_REPLACE_ELEM2(head, el, add, prev, next)                                               \
	do {                                                                                           \
		assert((head) != NULL);                                                                    \
		assert((el) != NULL);                                                                      \
		assert((add) != NULL);                                                                     \
		if ((el)->next == (el)) {                                                                  \
			(add)->next = (add);                                                                   \
			(add)->prev = (add);                                                                   \
			(head) = (add);                                                                        \
		} else {                                                                                   \
			(add)->next = (el)->next;                                                              \
			(add)->prev = (el)->prev;                                                              \
			(add)->next->prev = (add);                                                             \
			(add)->prev->next = (add);                                                             \
			if ((head) == (el)) {                                                                  \
				(head) = (add);                                                                    \
			}                                                                                      \
		}                                                                                          \
	} while (0)

#define CDL_REPLACE_ELEM(head, el, add) CDL_REPLACE_ELEM2(head, el, add, prev, next)

#define CDL_PREPEND_ELEM2(head, el, add, prev, next)                                               \
	do {                                                                                           \
		if (el) {                                                                                  \
			assert((head) != NULL);                                                                \
			assert((add) != NULL);                                                                 \
			(add)->next = (el);                                                                    \
			(add)->prev = (el)->prev;                                                              \
			(el)->prev = (add);                                                                    \
			(add)->prev->next = (add);                                                             \
			if ((head) == (el)) {                                                                  \
				(head) = (add);                                                                    \
			}                                                                                      \
		} else {                                                                                   \
			CDL_APPEND2(head, add, prev, next);                                                    \
		}                                                                                          \
	} while (0)

#define CDL_PREPEND_ELEM(head, el, add) CDL_PREPEND_ELEM2(head, el, add, prev, next)

#define CDL_APPEND_ELEM2(head, el, add, prev, next)                                                \
	do {                                                                                           \
		if (el) {                                                                                  \
			assert((head) != NULL);                                                                \
			assert((add) != NULL);                                                                 \
			(add)->next = (el)->next;                                                              \
			(add)->prev = (el);                                                                    \
			(el)->next = (add);                                                                    \
			(add)->next->prev = (add);                                                             \
		} else {                                                                                   \
			CDL_PREPEND2(head, add, prev, next);                                                   \
		}                                                                                          \
	} while (0)

#define CDL_APPEND_ELEM(head, el, add) CDL_APPEND_ELEM2(head, el, add, prev, next)

#ifdef NO_DECLTYPE
/* Here are VS2008 / NO_DECLTYPE replacements for a few functions */

#undef CDL_INSERT_INORDER2
#define CDL_INSERT_INORDER2(head, add, cmp, next)                                                  \
	do {                                                                                           \
		if ((head) == NULL) {                                                                      \
			(add)->prev = (add);                                                                   \
			(add)->next = (add);                                                                   \
			(head) = (add);                                                                        \
		} else if ((cmp(head, add)) >= 0) {                                                        \
			(add)->prev = (head)->prev;                                                            \
			(add)->next = (head);                                                                  \
			(add)->prev->next = (add);                                                             \
			(head)->prev = (add);                                                                  \
			(head) = (add);                                                                        \
		} else {                                                                                   \
			char *_tmp = (char *)(head);                                                           \
			while ((char *)(head)->next != _tmp && (cmp((head)->next, add)) < 0) {                 \
				(head) = (head)->next;                                                             \
			}                                                                                      \
			(add)->prev = (head);                                                                  \
			(add)->next = (head)->next;                                                            \
			(add)->next->prev = (add);                                                             \
			(head)->next = (add);                                                                  \
			UTLIST_RS(head);                                                                       \
		}                                                                                          \
	} while (0)
#endif /* NO_DECLTYPE */

#endif /* UTLIST_H */
